JP6113099B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus provided with a developer recovery device.

  For example, as disclosed in Patent Document 1, there is known a developer recovery device that sucks and recovers toner (developer) scattered by a developing device in an image forming apparatus. The developer collecting device includes a toner suction duct having a suction port provided in the vicinity of the developing device, and a toner collecting unit connected to the toner suction duct for sucking and collecting the scattered toner of the developing device through the toner suction duct. I have.

  However, the developer recovery apparatus described above has a problem that toner (developer) is accumulated in the toner suction duct. That is, it is difficult to completely collect the toner (developer) scattered by the developing device in the toner collecting unit, and there is a problem that the toner (developer) remains in the toner suction duct. When toner (developer) accumulates in the toner suction duct, the suction resistance in the toner suction duct increases and the recovery rate of scattered toner (developer) decreases.

  In view of this, the present applicant has proposed an image forming apparatus including an auxiliary fan (air assist means) for blowing air into the duct in the middle of the suction duct in order to suppress a decrease in the developer recovery rate (Japanese Patent Application). 2013-226706 etc.).

JP 2007-298782 A

  However, in the image forming apparatus provided with the auxiliary fan (air assist means), the blown toner (developer) may flow back to the developing device due to the operation of the auxiliary fan, and there is room for further improvement in this regard. is there.

  The present invention has been made in view of the above points, and provides an image forming apparatus capable of suppressing the backflow of toner (developer) to a developing device and further improving the recovery efficiency of toner (developer). With the goal.

The present invention includes a photoconductor and a developing unit that develops an electrostatic latent image on the photoconductor with a developer, and an image forming unit that prints an image developed on the photoconductor on a sheet;
A suction duct provided at one end in the vicinity of the developing device;
A suction fan and a filter provided upstream of the suction fan are accommodated while being connected to the other end of the suction duct, and the developer scattered by the developing device through the suction duct is sucked by the suction fan. And a developer recovery box to be adsorbed on the filter,
A vibration mechanism for vibrating the filter;
An auxiliary fan that blows air into the duct in the middle of the suction duct;
The gist of the present invention is an image forming apparatus including a control unit that drives the auxiliary fan during non-image formation and drives the developing unit when the auxiliary fan is driven.

  According to the present invention, since the backflow of the toner (developer) to the developing device can be suppressed by simultaneously controlling the driving of the auxiliary fan (air assist means) and the developing device, the toner (developer) Recovery efficiency is further improved.

1 is a block diagram illustrating a configuration of an image forming apparatus. FIG. 3 is a perspective view illustrating a configuration of a toner recovery device. It is a perspective view which shows the structure of a collection | recovery box. FIG. 3 is a block diagram illustrating a drive system of a toner recovery device. FIG. 3 is a perspective view illustrating configurations of a toner recovery device and a developing device. FIG. 3 is a perspective view illustrating a configuration of a toner recovery device. FIG. 3 is a front view illustrating a configuration of a toner recovery device. FIG. 3 is a front view illustrating a main part of the toner recovery device. FIG. 3 is a perspective view illustrating a main part of a toner recovery device. It is a time chart which shows one drive aspect of a developing device, an air assist fan, a suction fan, and a vibration motor. It is a time chart which shows one drive aspect of a developing device, an air assist fan, a suction fan, and a vibration motor. It is a time chart which shows one drive aspect of a developing device, an air assist fan, a suction fan, and a vibration motor.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiment.

  The image forming apparatus 1 according to the present embodiment is, for example, a laser printer or a multifunction peripheral, and is configured to form an image on a sheet based on image data transmitted from a terminal or the like (not shown) while conveying the sheet. ing. As shown in FIG. 1, the image forming apparatus 1 includes a paper feed unit 2, an image forming unit 3, a fixing unit 4, and a paper discharge unit 5.

  The paper feed unit 2 is a cassette paper feed unit or a manual feed tray that supplies paper to the image forming unit 3. The image forming unit 3 includes a developing device 11 and a photosensitive drum 12 (photosensitive member). In the image forming unit 3, an electrostatic latent image is formed on the photosensitive drum 12 by an optical scanning device (not shown), and the electrostatic latent image is developed by the developing device 11 to become a toner image that is a developer image. This toner image is transferred to the paper supplied from the paper supply unit 2. The fixing unit 4 includes a fixing roller and a pressure roller (both not shown), and fixes the toner image transferred to the paper by the image forming unit 3 to the paper. Thus, an image is formed on the paper. The paper discharge unit 5 has a paper discharge tray (not shown) to which the paper on which the image is formed is supplied from the fixing unit 4.

  Further, the image forming apparatus 1 includes a toner container 20 and a toner recovery device 30 (developer recovery device). The toner container 20 contains toner as a developer supplied to the developing device 11. The toner collecting device 30 sucks and collects the toner (developer) scattered by the developing device 11.

  The configuration of the toner recovery device 30 will be described with reference to FIGS.

  As shown in FIGS. 2, 5 to 7, and the like, the toner recovery device 30 includes a toner recovery box 40, and a suction duct 31 and an exhaust duct 35 connected to the recovery box 40.

  As shown in FIG. 3, the collection box 40 includes a box body 41 formed in a rectangular box shape. Inside the box main body 41, a substantially U-shaped passage 45 is formed by a passage forming member (not shown). In the box body 41, an inlet 42 is formed at a position corresponding to one end of the passage 45, and an outlet 43 is formed at a position corresponding to the other end of the passage 45. A suction duct 31 is connected to the inlet 42, and an exhaust duct 35 is connected to the outlet 43. One end of the suction duct 31 is located in the vicinity of the developing device 11 and can suck the toner scattered by the developing device 11 (see FIG. 5).

  The box body 41 houses a suction fan 46 (suction mechanism) and two filters 47 and 48 that adsorb toner. The suction fan 46 is provided at a position corresponding to the outlet 43 in the passage 45. The two filters are an upstream filter 47 and a downstream filter 48, and are sequentially provided on the upstream side (that is, the suction side) of the suction fan 46 in the passage 45. Of the two filters, the upstream filter 47 constitutes a filter according to the present invention.

  In the toner recovery device 30, by driving the suction fan 46, the toner scattered by the developing device 11 is sucked into the recovery box 40 through the suction duct 31 together with air. In the collection box 40, the sucked toner flows through the passage 45 and is adsorbed by the upstream filter 47. The toner that has passed without being adsorbed by the upstream filter 47 is adsorbed by the downstream filter 48. On the other hand, the air sucked into the collection box 40 together with the toner passes through the two filters 47 and 48 in order and flows from the outlet 43 to the exhaust duct 35. The air that has flowed into the exhaust duct 35 is finally discharged to the outside of the image forming apparatus 1. In this way, the collection box 40 sucks the toner scattered by the developing device 11 (toner around the developing device 11) by the suction fan 46, and adsorbs it to the filters 47 and 48 to collect it.

  Further, as shown in FIG. 4, the toner recovery device 30 includes a vibration motor 51 (vibration mechanism) that vibrates the upstream filter 47, an air assist fan 55 (auxiliary fan), and a control unit 60.

  The vibration motor 51 is configured to vibrate the upstream filter 47 to screen off the toner adsorbed on the upstream filter 47. Thereby, clogging by the toner of the upstream filter 47 is suppressed.

  As shown in FIGS. 2, 8, 9, etc., the air assist fan 55 blows air into the duct in the middle of the suction duct 31 and winds up the toner accumulated in the suction duct 31 by the blown air. .

  Specifically, the suction duct 31 has bent portions 32 and 33 bent at substantially right angles in the middle thereof. The air assist fan 55 is provided with two blowing passages 56 and 57. The first blowing passage 56 has one end connected to the air assist fan 55 and the other end connected to the first bent portion 32 of the suction duct 31. The second blowing passage 57 has one end connected to the first blowing passage 56 and the other end connected to the second bent portion 33 of the suction duct 31. That is, the air assist fan 55 is configured to blow air to the bent portions 32 and 33 of the suction duct 31 through the blowing passages 56 and 57.

  Further, as shown in FIGS. 8 and 9, the air assist fan 55 is configured to blow out air in the direction of suction of the toner by the suction fan 46. That is, the blow-out passages 56 and 57 are connected to the bent portions 32 and 33 so that the air blowing direction is the same as or substantially the same as the toner suction direction.

  As described above, by providing the air assist fan 55, the toner deposited in the suction duct 31 can be wound up. Therefore, the toner accumulated in the suction duct 31 can be easily sucked by the suction fan 46. This improves the toner recovery rate. In addition, since air is blown out to the bent portions 32 and 33 in which the toner easily accumulates in the suction duct 31, the toner accumulation in the suction duct 31 can be effectively suppressed.

  Further, since air is blown out in the suction duct 31 in the direction of suction of the toner by the suction fan 46, the accumulated toner can be flowed toward the collection box 40 as well as being wound up by the blown air. That is, the suction action by the suction fan 46 can be assisted. As a result, the toner accumulated in the suction duct 31 can be sucked more easily by the suction fan 46.

<Control action of control unit>
The control operation of the control unit 60 will be described with reference to FIGS. The control unit 60 drives and controls the developing device 11, the suction fan 46, the vibration motor 51, and the air assist fan 55. As a basic control, the control unit 60 is configured to stop the suction fan 46 and the air assist fan 55 when driving the vibration motor 51, and to drive the suction fan 46 when driving the air assist fan 55. Yes. That is, the control unit 60 is configured not to drive the air assist fan 55 and the vibration motor 51 at the same time.

  Further, when the number of developed images (number of printed sheets) exceeds the first predetermined value during the printing operation (or also during JOB) by the image forming unit 3, the control unit 60 performs the printing operation (or JOB by the image forming unit 3). When the number of developed sheets exceeds a second predetermined value higher than the first predetermined value during the printing operation (during JOB), the printing operation (JOB) is interrupted and The collecting operation is performed.

  In the present embodiment, the control unit 60 drives the air assist fan 55 during non-image formation (that is, at the end of the printing operation (JOB)), and drives the developing device 11 when driving the air assist fan 55. It is comprised so that it may be made into the state made to do. Here, the state in which the developing device 11 is driven refers to a state in which no developing bias voltage is applied.

  Further, the controller 60 is configured to increase (UP) the rotation speed of the suction fan 46 when the air assist fan 55 is driven.

  Specifically, as shown in FIG. 10, the control unit 60 drives the suction fan 46 in synchronization with the printing operation (JOB). Therefore, during the printing operation (during JOB), the toner scattered by the developing device 11 is sucked and collected in the collection box 40. When the number of developed images (number of printed sheets) exceeds a first predetermined value (for example, 1000 sheets) during the printing operation (during JOB), the controller 60 drives the suction fan 46 after the printing operation (JOB) is finished. The air assist fan 55 is driven while continuing. The air assist fan 55 is stopped after a predetermined time t1 (for example, 5 seconds), and the suction fan 46 is stopped after a predetermined time t2 (for example, 10 seconds). While the suction fan 46 and the air assist fan 55 are being driven, the toner scattered by the developing device 11 is sucked and collected in the collection box 40. Further, since the air assist fan 55 is driven, the toner accumulated in the suction duct 31 is also reliably sucked and collected. That is, the control unit 60 executes the collection operation.

  Subsequently, after a predetermined time t3 (for example, 3 seconds) after the suction fan 46 stops, the vibration motor 51 is driven for the predetermined time t4 (for example, 10 seconds). As a result, the toner adhering to the upstream filter 47 is sieved and clogging of the upstream filter 47 is suppressed. Then, after a predetermined time t5 (for example, 10 seconds) after the vibration motor 51 is stopped, a new printing operation (that is, the next JOB) is started. As described above, when the developing number exceeds the first predetermined value during the developing operation of the developing device 11, not only the suction fan 46 but also the air assist fan 55 is driven after the end of the developing operation. The toner can be reliably sucked.

  In the present embodiment, when the air assist fan 55 is driven at the end of the printing operation (JOB) (that is, during non-image formation), the developing device 11 is driven. Specifically, as shown in FIG. 10, when the air assist fan 55 is driven for a predetermined time t1 (for example, 5 seconds), the developing device 11 is driven for a predetermined time t1 ′ (for example, 5 seconds). That is, since the internal pressure of the developing device 11 can be increased and the backflow of the collected toner to the developing device 11 can be suppressed, the toner recovery efficiency is further improved.

  Further, the controller 60 is configured to increase (UP) the rotation speed of the suction fan 46 when the air assist fan 55 is driven. Specifically, as shown in FIG. 10, when the air assist fan 55 is driven for a predetermined time t1 (for example, 5 seconds), the rotation speed of the suction fan 46 is increased by the first 5 seconds of the predetermined time t2 (for example, 10 seconds) ( UP). That is, the toner suction force to the collection box 40 is increased more than usual, and the backflow of the toner diffused in the suction duct 31 to the developing device 11 can be further suppressed, so that the toner collection efficiency is further improved. To do. Further, since the rotation speed of the suction fan 46 is increased (UP) for the first 5 seconds of a predetermined time t2 (for example, 10 seconds), the power consumption can be suppressed by the minimum rotation speed UP of the suction fan 46, and the energy saving effect. It also leads to.

  Further, when the number of developed images (number of printed sheets) does not exceed the first predetermined value (for example, 1000 sheets) during the printing operation (during JOB), as shown in FIG. 11, after the printing operation (JOB) is finished, As in the case of FIG. 10, the controller 60 drives the suction fan 46, the air assist fan 55, and the developing device 11 for predetermined times t1, t2, and t1 ′, respectively. However, the suction fan 46, the air assist fan 55, and the developing device 11 are driven. The vibration motor 51 is not driven after stopping. This is because the amount of toner scattered by the developing device 11 is small, so that the amount of toner adhering to the upstream filter 47 is also small, and the possibility that the upstream filter 47 is clogged is low.

  In addition, when the number of developed images (number of printed sheets) exceeds a second predetermined value (for example, 5000 sheets) higher than the first predetermined value (for example, 1000 sheets) during the printing operation (during JOB), the control unit 60 displays FIG. A collection operation is performed as shown. Specifically, when the number of developed images exceeds the second predetermined value, the control unit 60 interrupts the printing operation (during JOB) and drives the air assist fan 55 while the suction fan 46 continues to be driven. The air assist fan 55 is stopped after a predetermined time t1 (for example, 5 seconds), and the suction fan 46 is stopped after a predetermined time t2 (for example, 10 seconds).

  Subsequently, after a predetermined time t3 (for example, 3 seconds) after the suction fan 46 stops, the vibration motor 51 is driven for the predetermined time t4 (for example, 10 seconds). Then, after a predetermined time t5 (for example, 10 seconds) after the vibration motor 51 is stopped, the printing operation (JOB) is resumed. As described above, when the number of developed images is considerably increased and the amount of scattered toner in the developing device 11 is considerably increased, the printing operation (JOB) is interrupted and the collecting operation is performed as an emergency. Thereby, it is possible to prevent the developing operation from being disturbed by the scattered toner.

  Further, according to the toner collecting device 30 of the above-described embodiment, when the vibration motor 51 is driven, the suction fan 46 and the air assist fan 55 are stopped, so that the toner sieved from the upstream filter 47 by the vibration motor 51 is sucked. It is possible to prevent the air from being sucked by the fan 46 and discharged to the outside. Further, since the suction fan 46 is driven when the air assist fan 55 is driven, the toner wound up by the air blown from the air assist fan 55 in the suction duct 31 can be reliably sucked into the collection box 40. Therefore, toner recovery can be performed appropriately.

  Furthermore, according to the toner collecting device 30 of the above embodiment, when the number of developed images exceeds the first predetermined value during the developing operation of the developing device 11, the collecting operation is executed after the developing operation of the developing device 11 is completed, and the developing device When the number of developed sheets exceeds the second predetermined value higher than the first predetermined value during the developing operation of 11, the developing operation of the developing device 11 is interrupted and the collecting operation is executed. That is, the collection timing is changed according to the number of developments. Thereby, even if the amount of scattered toner in the developing device 11 increases, the scattered toner can be reliably sucked and collected. Therefore, it is possible to prevent the developing operation of the developing device 11 and the printing operation of the image forming unit 3 from being disturbed by the scattered toner.

  In this embodiment, as in FIGS. 10 and 11, when the air assist fan 55 is driven at the end of the printing operation (JOB) (that is, during non-image formation), the developing device 11 is driven. Specifically, as shown in FIG. 12, when the air assist fan 55 is driven for a predetermined time t1 (for example, 5 seconds), the developing device 11 is driven for a predetermined time t1 '(for example, 5 seconds). That is, even when the number of developed images is considerably increased and the amount of scattered toner in the developing device 11 is considerably increased, the internal pressure of the developing device 11 can be increased and the backflow of the collected toner to the developing device 11 can be suppressed. Further, the toner recovery efficiency is further improved.

  Further, the controller 60 is configured to increase (UP) the rotation speed of the suction fan 46 when the air assist fan 55 is driven. Specifically, as shown in FIG. 12, when the air assist fan 55 is driven for a predetermined time t1 (for example, 5 seconds), the rotational speed of the suction fan 46 is increased by the first 5 seconds of the predetermined time t2 (for example, 10 seconds) ( UP). That is, the toner suction force to the collection box 40 is increased more than usual, and the backflow of the toner diffused in the suction duct 31 to the developing device 11 can be further suppressed, so that the toner collection efficiency is further improved. To do. Further, since the rotation speed of the suction fan 46 is increased (UP) for the first 5 seconds of a predetermined time t2 (for example, 10 seconds), the power consumption can be suppressed by the minimum rotation speed UP of the suction fan 46, and the energy saving effect. It also leads to.

  The present invention is useful for an image forming apparatus including a developer recovery device that sucks and recovers the developer scattered by the developing device.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 11 Developer 30 Toner collection device (developer collection device)
31 Suction duct 40 Collection box 46 Suction fan 47 Upstream filter (filter)
51 Vibration motor (vibration mechanism)
55 Air assist fan (auxiliary fan)
60 Control unit

Claims (5)

An image forming unit that prints an image developed on the photoconductor on a sheet, the photoconductor and a developing unit that develops the electrostatic latent image on the photoconductor with a developer;
A suction duct provided at one end in the vicinity of the developing device;
A suction fan and a filter provided upstream of the suction fan are accommodated while being connected to the other end of the suction duct, and the developer scattered by the developing device through the suction duct is sucked by the suction fan. And a developer recovery box to be adsorbed on the filter,
A vibration mechanism for vibrating the filter;
An auxiliary fan that blows air into the duct in the middle of the suction duct;
An image forming apparatus comprising: a control unit configured to drive the auxiliary fan during non-image formation and to drive the developing unit when the auxiliary fan is driven. The image forming apparatus according to claim 1.
The image forming apparatus, wherein the control unit is configured to increase a rotation speed of the suction fan when driving the auxiliary fan. The image forming apparatus according to claim 1.
An image forming apparatus in which a developing bias voltage is not applied when the developing device is driven. The image forming apparatus according to claim 1.
The image forming apparatus, wherein the control unit is configured not to drive the auxiliary fan and the vibration mechanism simultaneously. The image forming apparatus according to claim 1.
The suction duct has a first bent portion and a second bent portion bent at a substantially right angle in the middle thereof,
The auxiliary fan has a first blowing passage and a second blowing passage,
The image forming apparatus, wherein the auxiliary fan is configured to blow air to the first bent portion and the second bent portion of the suction duct through the first blowing passage and the second blowing passage.

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